Hot-fillable, blow-molded plastic containers are well known in the art. The problems associated with accommodating vacuum deformations associated with hot filling, capping and cooling, and their solutions are also well known. Typically, so-called vacuum flex panels are formed as relatively large indented panels in the sidewall of containers and accommodate the vacuum that develops in the containers as a result of hot fill processing. Examples of cylindrical containers having indented flex panels are disclosed in U.S. Pat. No. 5,762,221 issued to Tobias et al.; U.S. Pat. No. D.402,563 issued to Prevot et el.; U.S. Pat. No. D.366,831 issued to Semersky et al.; and U.S. Pat. No. D.366,416 issued to Semersky.
Hot-fillable blow-molded containers having multi-sided sidewall configurations with indented vacuum flex panels are disclosed, for example, by U.S. Pat. No. 5,178,290 issued to Ota et al. and U.S. Pat. No. 5,238,129 issued to Ota. In particular, FIGS. 7-8 of the Ota '290 patent and FIGS. 5-8 of the Ota '129 patent illustrate and disclose hexagonal and octagonal container sidewall configurations which have indented flex panels.
Hot-fillable, multi-sided containers have also been provided with a series of walls which are formed planar and which bow, flex, or warp inwardly in response to induced vacuum. Thus, the resulting shape of each panel of such hot-filled, capped and cooled containers is concave, or inwardly bowed, thereby providing the sidewall with an undulating shape in plan. Examples of such containers are disclosed by U.S. Pat. No. 4,749,092 issued to Sugiura et al. and U.S. Pat. No. 4,497,855 issued to Agrawal et al. For instance, see FIGS. 2 and 5 of the '092 Sugiura patent and FIG. 7 of the Agrawal '855 patent. U.S. Pat. No. 3,923,178 issued to Welker, III discloses another multi-sided container having a plurality of sidewall panels which, as-formed, are planar and which are designed to flex inwardly. For instance, see FIG. 7 of the Welker, III '178 patent.
Other related container designs are disclosed by U.S. Pat. No. 4,946,053 issued to Conrad which discloses an ovalized label panel for a hot-fillable bottle having a circular footprint; U.S. Pat. No. 5,908,127 issued to Weick et al. which discloses an ovalized or “rounded-off” rectangular sidewall of a hot-fillable bottle having front and rear outwardly bowed panels; and U.S. Pat. No. 5,690,244 issued to Darr which discloses a paneled sidewall of a jar having a circular footprint. Also see the container configurations disclosed in U.S. Pat. No. 4,818,575 issued to Hirata et al.; U.S. Pat. No. 5,866,419 issued to Meder; U.S. Pat. No. D.189,372 issued to Adell; U.S. Pat. No. D.402,896 issued to Conrad; U.S. Pat. No. D.318,422 issued to Rumney; U.S. Pat. No. D.418,760 issued to Blank; and U.S. Pat. No. D.419,886 issued to Gans.
A problem experienced with hot-fillable containers having flex panels, particularly indented or concave flex panels, is that voids are created within the label mounting region behind the labels. Voids behind a label can prevent the label from being prominently displayed on the container sidewall and can provide areas on the label which are prone to tearing, undesirable stretching, or the like. In addition, the use of certain labels, such as shrink wrap labels, can result in the labels extending into, or shrinking within, the voids which also negatively effects container aesthetics.
Another problem experienced with hot-fillable containers is the occurrence of creases, dents or like deformations in the sidewalls of the containers which damage, weaken, and/or detract from the aesthetics of the container. Such deformations can result, for instance, due to line pressure experienced during transferring, filling, capping and packing operations. To this end, adjacent containers in such operations can become tightly engaged, particularly adjacent the base and lower bumper areas of the containers, thereby causing at least selected ones of the containers from being dented or provided with undesirable crease marks. More specifically, multi-sided containers typically experience such deformations adjacent the vertical post structures adjacent the base of the containers.
A still further problem relates to the occurrence of creases, dents or like deformations in the sidewalls of the containers experienced as a result of shipping and handling of the containers due to inadequate top loading or drop capability. To this end, creases or dents can result in containers located in bottom rows of containers on which many other rows of containers are stacked during shipping. In addition, forces exerted on the containers during loading and unloading of the stacked containers can also cause creases and dents. Multi-sided containers are particularly prone to such deformation along post structures adjacent the base of the containers along an area of contact of the containers with adjacent containers in the stack.
Although various ones of the above referenced containers may function satisfactorily for their intended purposes, there is a need for a hot-fillable, blow-molded container having a flex panel and sidewall structure which permits a label to be completely wrapped around the container sidewall and prominently displayed thereon and which limits voids behind the label. In addition, preferably the sidewall structure should be multi-sided and should be reinforced to resist creasing, denting and the occurrence of like deformations. Further, the container should provide improved top loading capability and improved drop testing results. Still further, the container should be capable of efficient and relatively inexpensive manufacture and should be capable of being made from a minimum of thermoplastic material.